Question

Experiments on learning in animals sometimes measure how long it takes mice to find their way through a maze. The mean time is 18 seconds for one particular maze. A researcher thinks that a loud noise will cause the mice to complete the maze faster. She measures how long each of 10 mice takes with a loud noise as stimulus. The appropriate hypotheses for the significance test are

a. $H_0:\mu =18;H_a:\mu \ne 18$

b. $H_0:\mu =18;H_a:\mu >18$

c. $H_0:\mu <18;H_a:\mu =18$

d. $H_0:\mu =18;H_a:\mu <18$

e. $H_0:\overline{x}=18;H_a:\overline{x}<18$

Short answer

Option (d) is correct.

Step-by-step solution

Given Information

It is give that mean time for maze is $18$seconds.

Explanation

We will conduct hypothesis for population parameter (not sample statistics).

The null and alternate hypothesis are as below:

$H_0:\mu =18$

$H_a:\mu <18$

For completion of maze faster, time need to be decreased. therefore test is left tailed.